southpawboston

My commuter bike with Pasela Tourgaurds lives outside all year except whenever there's snow and/or significant salt on the ground (my area goes nuts with road salting). I just got my first flat on these tires after about two years of mostly year-round commuting, very short distances but frequent (averaging about 25 miles a week, and probably about 1000 miles per year, so I'm guessing the tires have about 2000 miles on them). When I removed the tire for inspection, I noticed that the tread is only a little worn. However, the tread is split in at least a couple dozen places, deep splits, all the way down to the casing. It's a wonder it hadn't flatted sooner! In addition, the tan sidewall is dried and cracked all over, and the nylon casing fibers are splitting and sticking out of the side wall like hair. The front tire looks as bad, but has less tread wear.

I noticed similar tread cracking on a set of Schwalbe Marathons, also on a bike that gets left out mostly during the summer months.

I also have Pasela Tourguards on a long distance bike that I ride about 500-1000 miles a year doing mostly 20-100 miles rides, but keep stored indoors. This bike rarely see daylight! On this bike the Tourgaurds look fantastic, no rubber splitting, no cracking. But there is tread wear, at least as much as on my commuter.

So my conclusion is that exposure seems to do more harm than actual usage. Ostensibly I would attribute this to UV exposure more than water or temperature extremes, but was wondering if others have experienced this as well? Are bike tires not made to be UV-resistant? I don't notice similar patterns of disintegration on car tires...

cny-bikeman

UV is the main problem. You can apply UV protectant to the tires to help somewhat, but wipe it on so that you aren't applying it to the rims.

GamblerGORD53

I used to have the same problem with goofy color sidewalls, especially with Conti tires.
Since then I have been using Schwalbe Marathon Plusses which have zero problem with cracking.
I've also had one Conti Tour Plus front tire the last 4 years with 6,000 miles. The surface layer started cracking between the treads at 1200 miles and the cracks kept getting bigger. The wad of padding held it together OK and it had no flats.

Some brands just have a better rubber recipe.

FBinNY 

Open, gum, para, or latex (all basically the same thing) sidewalls such as those on tubulars are very vulnerable to UV damage as are brake lever hoods, and sometimes cable housings.

However, normal blackwall tires, as are most clinchers, are very resistant. The walls are covered with the same synthetic rubber as the tread, and can tolerate years of sunlight exposure. They're made of the same stuff as auto tires and if UV were an issue, there would be all sorts of warnings.

OTOH, even excellent resistance doesn't mean tires may not be affected over long periods of UV exposure, so if you don't ride much, you may want to set a UV shelf life of 5 years or so.

GamblerGORD53

Actually, car tires do have the same problem. A few months ago on my low mileage 8 1/2 year old car/tires I had a nail go thru the corner /side = toast. OEM tires are generally cheap and poor in the winter and were getting worse from age hardening. The dealer said they consider tires older than 5 years are past their best before date, so need to be avoided. So I ended up with 4 new tires. One of the AL rims keeps leaking like a seive, stupid corrosion.

FBinNY 

Yes, as I said, resistance to UV and Ozone doesn't mean immunity, which is why I set 5 years of outdoor storage as a rough guideline for shelf life.

The auto tire industry an the USDOT have been discussing some kind of dated life guideline for tires for years, but last I checked no mandatory limit has been passed, possibly because most tires are worn out by that time, making it an issue affecting only a small minority of drivers.

furballi

I run Michelin City, where the sidewall is the same material as the whole tire. No visible cracking after 2.5 years. Rear 32c is good for at least 12K miles.

Burton

Car tires are affected exactly the same way.

Chombi

There are things indoors that can also harm tires.....like ozone gas generated by big electric motors.
If you store the bike indoors, just remember to keep it away from any large electric motors like fans in a furnace. or sump pumps. Sowtch out if these things are in the basement with our bikes.....
The ozone gas will dry rot the tires in quick time. Had it happen to my motorcycle tires once when I lived at an aparment complex. Made the mistake of parking the bike near the mechanical room (where they had the furnace nd I think some elevator hydraulic pump equipment) grille vent in the parking level. Tires dried up and cracked all over really bad within a year, and I had to replace them. Bicycle tires, being more delicate in construction, will be more vunerable. Best to keep them in a living space away from these electric motors....

dddd

Where I live, outdoor storage, or even in a well-ventilated garage, causes cracking of tire rubber in a relatively short time even when no UV is hitting the tires.

Indoors, Ozone is readily attracted to organic materials throughout the house, greatly reducing the concentration in the air.
On the roof of a speeding car, a tire will suffer the highest rate of ozone absorption, not to mention UV exposure during daylight.

Many Michelin and certain other European tires seem to have the shortest rubber lifespan due to cracking. Their rubber can be very different.
I remember Michelin folding tires that pretty quickly developed gaping cracks while hanging on the hooks folded in the store.

cyccommute 

Probably not. Ozone is more likely the culprit. Bike tires, being thin, suffer more from oxidation than car tires do. You are correct that a protectant would help, however. It helps act as a barrier against ozone as well. Keep it off the treads.

fietsbob

Got a Tarp to cover the bike while it's parked outside?

dramiscram

I had a tire problem yesterday and posted it on the commuting forum (I'm a commuter)
The rear started to wiggle while on my way to work, almost the same feeling you get when break a spoke.
when I got there I checked all the rear spokes to see if I could get home on the bike after work but all the spokes were fine.
So I spinned the wheel to see what was wrong and the tire looked out-of-round.
I checked more closely and there's what I found


The whole tread is separating from the casing.

It's a tire I got with a bike I bougth for parts (cracked frame), it came from an Allez 2005 so the tire is at least 8 y/o
I use it just once in a while as it is on my spare wheel ( my regular wheel as a broken spoke that I need to replace this weekend)
So I ended up with a new tire
Is it because the tire is old? I hope not because I have older michelin on my vintage Bianchi that are performing very well and look very good.
Anyone ever had a tire do this?

FBinNY 

It isn't at all rare (though not common either) for treads to separate this way on higher end tires where the tread and sides aren't molded in a dingle operation.

Better ties have the tread layers molded separately and glued onto a prepared tire body. Weathering, and to a degree mechanical stress from riding at low pressure can break the glue bond and lad to delamination.

It isn't a problem unique to bike tires. Retreaded truck tires have been doing this for decades, and I believe the issue is why recapped auto tires don't exist anymore.

While it's hard to set a time limit, you have to consider that tires have an age limit, besides the normal wear limit. I don't worry about the minor checking or hairline cracks in the rubber, but as tires begin to show age, they need to be visually inspected occasionally to avoid surprises on the road.

BTW- if your tire is otherwise in good shape and worth saving, the tread can be reglued with a good rubber adhesive. I use 3m Fasttack for this kind of work on tubulars.

FMB42

That's a good question/advice Fietsbob.


And yes, UV and ozone (to a larger extend imo) can and do destroy tires.

A case in point is the year 2000 truck that my wife recently bought. This vehicle was in good condition for being a 13 year old truck (w/~ 125K miles). The exception to this were the name brand tires, which were badly cracked on all 4 sidewalls. The sad thing is that the treads looked almost like new (and no, they weren't "retreads"). That all 4 were bad suggests that old age and/or ozone were the cause. I did not verify the age of the tires, but my I guess that they were installed when the truck was about 6-8 years old (the seller claimed that the truck was driven regularly up until about 2007 when the owner retired).

I do know that I've seen at least one motorcycle that had tires that were sun damaged when the bike was stored outside and uncovered in such a way that the sun only hit one side (the tank, seat, and side covers were also sun damaged on the same side).

SJX426 

Yes and they are not safe as they are hard. I rode with a friend who had checked tires on his motorcycle and crashed on a corner. I am convinced it was his old tires.

dddd

"BTW- if your tire is otherwise in good shape and worth saving, the tread can be reglued with a good rubber adhesive. I use 3m Fasttack for this kind of work on tubulars."


I kind of find it refreshing that there are still people who will have a go at fixing disposable stuff to get full useful life from a product instead of discarding it.

Would I do this? Probably not, but perhaps only because I know that I can find a better tire, usually the front tire of a discarded pair, that someone at the shop is discarding.

I've myself patched many tire casings from the inside, but I treat this as a very pressure-sensitive proposition, i.e. usually ok with reduced inflation pressure.

bradtx

southpawboston, IIRC ozone contributes to the hardening of the rubber while UV light and to a lesser extent ozone contribute to the 'weathering' cracks. Inexpensive auto tires (those not advertized as high mileage), and bicycle ties in general don't have the additives to slow the reactions.

Brad

PS I do think the five year rule is a good one. I do have the last of my GP3000 tires on my roadie which are older than five years, but stored unmounted in an indoor closet. I don't expect in-service life to be as good as if the tire was more freshly manufactured.

laingjscott

I have noticed that cracking happens on both old and new bike and car tires if I don't use them regularly such as with a car sitting in the driveway for weeks to months while waiting to be fixed and also with my bikes that sit in our hot garage without being used for a year at a time sometimes. Here is what I found supporting that and other comments about UV rays and ozone: https://www.tirerack.com/tires/tirete....jsp?techid=37

habilis

You folks who store bikes outside: Don't you find rust to be as much of a problem as UV light? Are the bikes at least sheltered from rain?

practical

I used to hang my bikes up in my carport. The sun would shine on them during the day. Tires would last a year, maybe two, as the sidewalls became dry and cracked. Now I store my bikes in a shed. No tire problem. Lesson - avoid storing bikes in direct sunlight.

Gresp15C

What produces the ozone?

ThermionicScott 

If your tires are as old as this thread, you probably don't ride enough.

Dave Cutter

I take my tires out in the sunlight nearly every chance I get. Sometimes It rains on my bicycle (and me) before I get home. If I suspect it might rain I ride my rain bike. But only once have a guessed correctly and been on the rain bike... when caught in the rain. But I wash all my bikes regularly so they're accustomed to getting wet. I haven't noticed any rust problems yet.

I could just keep my bikes inside on trainers and never take them outside. I do store my bike inside. But I think if cared for they do OK outside too. Tires don't last forever.

ramzilla

All the chemicals used in tire manufacturing break down over time. My dad bought a set of truck tires on sale once and stored them in the basement. In the meantime, he quit driving the truck & forgot all about the tires. I got the truck running again about ten years later. Mounted the new looking tires on it. They didn't last 1000 miles. Big cracks appeared in the face along the tread grooves. Exposing the belts underneath. Wow! I could have had a savage blow out! Good thing I noticed it in time.